The present invention relates to a device for and a method of testing a fire alarm.
It is known that fire alarms have to be tested in cyclic time intervals. Some devices and methods for testing fire alarms are known. They can be further improved.
Accordingly, it is an object of the present invention to provide a device for and a method of testing a fire alarm, which is a further improvement of the existing devices and methods.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a device for testing a fire alarm, in which the device has at least one testing gas for the at least one gas sensor, which is available in a testing pot.
In accordance with a new method of the invention, together with operational testing of a smoke alarm, an operational testing of at least one gas sensor of the fire alarm is performed with at least one testing gas.
The inventive device and method for testing a fire alarm has the advantage that for a fire alarm, which has a smoke alarm and at least one gas sensor, in one working step the smoke alarm and the at least one gas sensor are tested with respect to their operational ability. Thereby the operational testing of the fire alarm is simplified and accelerated. Moreover, the inventive device represents a testing apparatus which provides all stimuli for the available sensors (smoke alarm, gas sensor, temperature sensor) of the fire alarm.
It is especially advantageous when in accordance with the present invention the aerosol is used for the smoke alarm and the testing gas is used for the at least one gas sensor in separate gas containers in the inventive device, so that individually the gasses are exchangeable and storable individually.
Moreover, advantageously the at least one testing gas and the aerosol can be stored in one gas container, so that space for a further gas container in the inventive arrangement is saved. This simplifies the storage and the replacement of the aerosol with the testing gas. It is further advantageously possible that the testing gas and the aerosol are identical, which significantly saves the expenses for the construction and the operation of the inventive device.
It is further advantageous when as the testing gas, methanol or ethanol or hydrogen are utilized, which due to a cross sensitivity of the gas sensors are usable for the operational testing. Cross sensitivity of a gas sensor means that a gas sensor supplies a detection signal not only for the gas for which it is designed but also for another gas, wherein methanol, ethanol and hydrogen are especially suitable for this purpose. There is therefore the advantage that the hydrogen which is generally difficult to store, here is recovered for the operational testing by electrolysis from a sodium sulfate solution to make the hydrogen available only when needed. The alcohols such as methanol and ethanol provide in addition the possibility to operate as aerosols.
Its another advantage that a gas outlet opening is oriented to a temperature sensor of the fire alarm, to force a temperature lowering at the temperature sensor through the gas outlet, which is usable for an operation test of the temperature sensor. Thereby three different measuring principles are tested in a single step at the fire alarm with respect to its operational ability.
It is further advantageous when the valves are operated mechanically or electromechanically. With an automatic actuation, timely opening sequences are adjustable, which are considered as advantageous for an optimal simultaneous testing of the smoke alarm and the gas sensor. Thereby the use of the testing gas and aerosol can be optimized.
In accordance with another feature of the present invention, it is advantageous when the gas containers are formed as spray boxes. Thereby the mounting and the use of them are significantly simplified.
Finally, it is advantageous when in accordance with the present invention a fire alarm which must be tested with respect to its operational ability is provided with means for switching to one testing mode, and also has means for signaling whether the fire alarm is operational or not. It is especially advantageous to determine which sensor of the smoke alarm, the at least one gas sensor or the temperature sensor, are operational or not. This can be provided in connection with a safety network which is monitored by a central unit and to which the alarm to be tested is connected. The fire alarm in the testing mode signals to the central unit whether the operational ability of the available sensors (smoke, gas, temperature) is provided or not. As a safety network, for example the known LSN (local safety network)-bus can be used.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.